Fountain Pyrometer for Strip Temperature Measurement in Cooling Banks of the Hot Strip Mill

Abstract

Sumitomo Metal Industries, Ltd. (SMI) developed a new temperature measurement method (Fountain pyrometer) and associated control system, for hot strip cooled by water in cooling banks. Use of the Fountain pyrometer and control system achieved very precise temperature control of hot strip in the run-out table.
Recently, high tensile steel has been applied to lightweight cars as a measure to reduce CO₂. In order to stabilize material quality of a hot strip including high tensile steel, the temperature control in run-out table is important. But the accuracy of the conventional control was not good enough because the temperature of a hot strip couldn't be measured in cooling banks that had much cooling water, which disturbs thermal radiation from the hot strip surface and the stable measurement of hot strip temperature.
SMI has developed Fountain pyrometer, which uses water purge to stabilize the optical pass of thermal radiation from hot strip surface. It was confirmed that Fountain pyrometers are reliable to measure hot strip temperature even in cooling banks where much cooling water exists. The range for Fountain pyrometer is above 360°C and its responsiveness is less than 20 ms. SMI also developed a new control system to use the Fountain pyrometers. Use of Fountain pyrometers and the control system achieved very precise temperature control of hot strip in the run-out table.